Post-traumatic hydrocephalus.

The syndrome of post-traumatic hydrocephalus (PTH) has been recognized since Dandy's report in 1914. The incidence of symptomatic PTH ranges from 0.7%-29%. If CT criteria of ventriculomegaly are used the incidence has been reported to be from 30%-86%. Differences in diagnostic criteria and classification have contributed to the variation in reported incidence. The diagnosis of PTH is established using a combination of clinical, imaging and physiologic data. Symptomatic PTH is to be distinguished from post-traumatic ventriculomegaly resulting from atrophy. Symptomatic PTH patients are likely to improve when treated by shunting. Ventriculomegaly secondary to atrophy is less likely to respond to shunting. A series of traumatic brain injury patients at Wayne State University has been followed since 1989. The overall incidence of shunt placement in this group is 3.65%. Future studies of PTH should be aimed at refining diagnostic classification and criteria. Analysis of a large PTH population may then identify alterable risk factors in the early post-traumatic brain injury period. Minimizing these factors will help prevent subsequent PTH and obviate the need for shunting.